This invention is directed to a method for performing a minimally invasive coronary artery bypass graft. More particularly, the method permits a thoracoscopic procedure without the need for extracorporeal circulation or other cardiopulmonary bypass.
A coronary artery bypass graft (CABG) involves performing an anastomosis on a diseased coronary artery to reestablish blood flow to an ischemic portion of the heart muscle. Improved long-term survival has been demonstrated bypassing the left anterior descending artery (LAD) with a left internal mammary artery (LIMA). Loop, F. D., Lytle, B. W., Cosgrove, D. M., et al. xe2x80x9cInfluence of the Internal Mammary Artery on 10 Years Survival and Other Cardiac Events,xe2x80x9d N. Eng. J. Med., 1986; 314:1-6. This has encouraged surgeons to extend revascularization with arterial grafts to all coronary arteries. In multiple-vessel disease, other arteries have then to be used, such as: the right internal mammary artery (RIMA), the right gastroepiploic artery, the inferior epigastric artery and the radial artery. At the same time, other techniques are also being used: arterial sequential anastomosis and/or graft elongated and/or Y- or T-grafts. Calafiore, A. M., DiGianmarco, G., Luciani, N., et al. xe2x80x9cComposite Arterial Conduits for a Wider Arterial Myocardial Revascularization.xe2x80x9d Ann Thorac. Surg., 1994:58:185-191 and Tector, A. J., Amundson, S., Schmahl, T. M., et al. xe2x80x9cTotal Revasculization With T-Graftsxe2x80x9d. Ann Thorac. Surg., 1994:57:33-39.
Traditionally, bypass graft procedures have required opening the chest wall via a sternotomy, stopping the heart and supporting the patient with a cardiopulmonary bypass system. These requirements are extremely invasive, pose significant risks, require lengthy hospitalization and are expensive. In hope of overcoming these and other problems, physicians have developed a number of alternatives such as percutaneous transluminal coronary angioplasty (PTCA), atherectomy, placement of stents and pharmacological treatments. The most common of these is PTCA which offers relatively short hospitalization periods and is relatively inexpensive. However, these benefits are mitigated by a significant restenosis rate. Similarly, the other alternatives suffer from their own drawbacks.
For these and other reasons, providing an anastomosis between an internal mammary artery and the LAD may be the best therapeutic option for severe proximal lesions. Benetti, F. J., Rizzardi, J. L., Naselli, G., et al., xe2x80x9cAnastomosis Manerio Coronaria Sin Circulatixc3x3n Extracorpxc3x3rea,xe2x80x9d Prense Mxc3xa9dica Argentina, 1985; 73:213. Accordingly, there is a need for improved CABG procedures that simplify surgical techniques and diminish hospital stays and costs.
The invention comprises a method for performing CABG procedures without the need for opening the chest wall, stopping the heart or providing cardiopulmonary bypass. Generally, at least one small opening is formed in the patient""s chest, a target artery for an arterial blood supply is located through an opening in the patient""s, chest, instruments are introduced through one or more small openings formed in the patient""s chest to separate the target artery from its support base; and instruments are introduced through one or more small openings formed in the patient""s chest to connect the target artery to a portion of a coronary artery distal from a stenosis in fluid communication therewith to supply arterial blood from the target artery thereto. In a preferred embodiment, a minimal left anterior intercostal thoracotomy provides access to form the anastomosis between the left internal mammary artery (LIMA) and the left anterior descending artery (LAD) while thoracoscopic viewing facilitates harvesting the LIMA. In other embodiments, access to the patient""s heart may be obtained through a trocar sheath or other means for providing percutaneous access to the patient""s thoracic cavity without opening the chest wall. Depending on the type of access, thoracoscopic visualization is used to locate the arterial blood supply, the location of the coronary artery to be bypassed or the location of the occlusion in the artery. In other embodiments, the diagonal (Dx) or circumflex (Cx) arteries may be bypassed.